Horizontal autoclave tanks are provided with a removable cover which must be sealed hermetically. A material holder which may receive the textile material to be treated in the form of a beam of woven or knitted fabric or a reel of yarn may be introduced into the tank generally by means of lateral rails on which it travels by means of rollers with which it is provided.
In general, the cover is able to pivot and the withdrawal of the material holder is achieved by using a movable transportation carriage which may receive the material holder.
The horizontal autoclave tank is provided with a circulation unit which provides for the circulation of a stream of fluid through the tank and in particular the stream is directed so that it passes through the centre of the textile material to be treated. This circulation unit is generally provided with a cone on which the beam supporting the piece of wound fabric is fitted. The beam comprises a multitude of orifices on its periphery through which passes the stream of treatment fluid which thus penetrates to the actual centre of the roll of woven or knitted fabric. The cone around which the beam fits makes it possible to connect the latter directly to the circulation pump of the unit which thus supplies the inner volume of the hollow beam with treatment fluid.
The horizontal autoclave tank also comprises a series of valves which allow the introduction or elimination of components necessary for carrying out the treatment operation, as well as the necessary safety valves.
Furthermore, the treatment installation comprises an open or closed injection tank as well as an auxiliary injection pump. The autoclave tank is connected to the injection tank through the intermediary of a pipe equipped with a flow-regulating valve. Thus, in particular, increases in the volume of treatment liquid present in the autoclave tank, on account of a temperature rise, are absorbed by the injection tank. Moreover, the residual fluid in the injection tank is returned to the horizontal autoclave tank through the intermediary of an auxiliary injection pump. A permanent circulation of the fluid between the injection tank and the autoclave tank thus occurs. In the case of an open injection tank, it is necessary to provide a high pressure auxiliary injection pump in order to repressurize the fluid before its introduction into the autoclave tank.
In fact it is necessary to keep the autoclave tank under pressure in order to prevent the treatment fluid from being able to vaporize, in particular in the vicinity of the impeller of the circulation unit by a cavitation effect.
It should also be noted that the presence of an attached injection tank has numerous drawbacks. On the one hand, this makes it necessary to use a volume of treatment fluid greater than that strictly necessary, if only to fill the pipes which connect the autoclave tank to the injection tank. Moreover, the characteristics of the treatment fluid present in the injection tank do not necessarily correspond to those of the fluid present in the autoclave tank, in particular, the temperatures may be substantially different and the emptying of the bath present in the injection tank may be less than that present in the autoclave tank, for example, because the dye of the fluid in the injection tank may not yet be transferred to the textile material.
Consequently, the treatment fluid which is returned to the autoclave tank through the intermediary of the auxiliary injection pump has characteristics different from the main bath present in the tank and consequently local non-homogeneity of the bath may follow, which will cause a dyeing fault.